Self sealing fitments which eliminate the need for a conventional closure intermediate dispensing cycles are generally known in the art. For example, U.S. Pat. No. 2,175,052 issued to Bull et al. on Oct. 3, 1939 discloses a dispensing closure for attachment to containers for materials such as toothpaste, shaving cream, etc. to which internal pressure is applied to discharge the contents therefrom. According to Bull et al., the invention comprises a cap having a flexible, stretchable resilient member for attachment to the end of a dispensing container, the member being so constructed in proportion that, at least during operation, stresses and strains in the resilient member are directed toward the central end portion of the cap. In the illustrated embodiment, the Bull et al. invention is in the form of a cap having a tubular body open at one end and closed at the other end. The body is made of flexible, stretchable resilient material, preferably a vulcanized, soft, elastic rubber composition. An end wall is connected to the tubular sidewalls by means of an intermediate portion having a thickness less than that of the sidewalls. The end wall is located in such manner that it lies wholly within the tubular portion of the body, i.e., in a reentrant position. Preferably, the intermediate portion forms a frusto-conical outline in which the end having the smaller diameter unites with the end wall. A slit extends through the wall member, and a depression in the form of beveled surfaces adjacent the slit is formed in the end wall on the innermost side relative to the tubular body. The cap is connected to a conventional dispensing container such as a tube having a collapsible body made of material such as lead foil.
When the dispenser cap of Bull et al. is applied to a container, and pressure is exerted upon the container, the dispensing material is forced against the inner side of the end wall, with the result that the wall is carried outwardly. The relatively thin wall of the intermediate portion permits outward movement of the wall upon the application of pressure from within. As pressure is exerted against the dispensing material the end wall becomes distended and the slit, which is normally in a closed state, opens to permit extrusion of material from the dispensing container. When manual pressure on the dispending container is relieved, the end wall and its adjacent portions return, at least in part, to their normal, unstrained condition. During this return movement of the end wall, and when the wall is in a position substantially in the same plane as that defined by the outer end of the tubular body, as shown in FIG. 4 of the drawings, compression stresses and strains are set up in the end wall. According to Bull et al., these compression stresses and strains result from the compression stresses present in the intermediate portion when the intermediate portion becomes confined between the end wall and the tubular body during axial movement of the end wall relative to the tubular body. In this position, and as shown in FIG. 4, the compression stresses and strains present in the wall cause the surfaces defining the slit to move tightly together, thus shearing off a strip of the dispensed material. After the dispensing assembly remains in a state of rest for a short period, the cap allegedly returns to its normal, unstrained state, as shown in FIG. 1.
An alternative prior art container closure of the self-sealing variety is disclosed in U.S. Pat. No. 1,825,553 issued to Smith on Sept. 29, 1931. Smith discloses a collapsible tube which is preferably soft and flexible and may serve as a receptacle for dentifrice, shaving cream, paste, or other viscous substances. In the illustrated embodiment, the tube is provided with a relatively stiff conical end portion integral therewith, and an externally threaded neck integral with the end. The neck is provided with a large bore adjacent the end portion and a smaller cylindrical bore extending from the large bore through the top surface of the neck. The shoulder at the juncture of the bore is chamfered to form a conical seat.
The tube closures of Smith are preferably made in molds from a good grade of rubber and vulcanized to attain the desired elasticity. A tube closure such as shown in FIGS. 1-12 inclusive of Smith comprises a base and an end portion. The shoulder at the juncture of the bore and end portion is beveled to conform with the conical seat of the tube neck. The end is so arranged as to form a cavity in the base, and extending from this cavity through the end a valve slit is provided. To mount the closure in the neck of the tube it is only necessary to insert the closure through the large end of the tube ino the neck until the beveled shoulder of the closure rests across the conical seat of the neck. The tube is then filled with suitable material in the usual manner and may be supplied with a metal screw cap to protect the valve closure until delivery to the user.
In the embodiment illustrated in FIG. 14, the closure in question comprises a base and an end portion. The juncture of the base and end portion is chamfered to conform to the seat of the tube. The base is provided with a conical cavity and has its inner bottom edge chamfered to facilitate the entrance into the cavity of the tube contents when the same is being extruded. The top surface of the end portion is concave and has a valve port which may be of any of the shapes disclosed in the patent.
To extrude contents from the tube Smith discloses that it is only necessary, after the cap has been removed, to apply pressure to the tube and this pressure will froce the contents of the tube against the top of the cavity of the closure and cause the valve slit to open and allow the tube contents to pass out as shown in FIG. 3. When the pressure on the tube is released, the elasticity of the closure member allegedly forces the slit tightly closed and prevents any further extrusion of the contents.
Still another prior air collapsible tube structure is disclosed in U.S. Pat. No. 1,206,661 issued to Booth on Nov. 28, 1916. Booth discloses a collapsible tube which is provided at one end with a tubular outlet, externally theaded to receive a closure cap. In practice, the tube is filled through its opposite end, which is normally open, and is folded or rolled upon itself, to form a closure at that end in the usual manner. The material contained in the tube is discharged by folding or rolling the folded or rolled end upon the body of the tube, by compressing the tube between the thumb and fingers of the hand, or by using an expressing device of suitable construction.
Within the tube of Booth is disposed a suction or vacuum producing device shown in the form of a dome-shaped or cup-shaped body of rubber or other elastic material. This cup-shaped body has its open side facing the top of the tube and provided with a thickened rim edge to bear against the top of the tube to form therewith a suction or vacuum chamber. At its center the diaphragm cup is provided with an outlet in the form of a slit which is normally closed by the elasticity of the material when parts of the diaphragm are in normal position, as shown in FIG. 1. In expelling the material the pressure of such material on the bottom of the diaphragm causes such portion of the diaphragm to be elevated or forced into the cup toward the outlet, thus expanding the slit to form a circular opening for the outward passage of the material. When the pressure upon the diaphragm is removed, the deflected portion thereof allegedly returns to normal position by its own elasticity, thus producing a suction or partial vacuum in the vacuum chamber, whereby the excess material discharged will be drawn back into the tube. According to Booth, the form of elastic cup shown in FIGS. 1 and 2 may be used where the material stored and dispensed is comparatively light in weight and of a more or less readily flowing character. However, for heavier and denser fluids, and thus having some material degree of viscosity, the diaphragm is preferably employed in conjunction with a spring, as shown in FIG. 3, to return the deflected portion of the cup positively to normal position after actuation.
U.S. Pat. No. 2,758,755 issued to Schafler on Aug. 14, 1956 discloses still another compressible container with an automatically closing and retracting discharge nozzle. Schafler discloses a cupped membrane part of resilient material of suitable plastic or rubber substance as the closure of a compressible tube, bottle or other container. The cupped membrane may be an integral part, as shown in FIGS. 2 and 3, or it may be a separate part clinched on as an extension, of, for instance, the tube which is of compressible nature as it would be if made of metal foil. The interior surface of the bottom of said cupped part is formed with an annular channel surrounding a central well, whereby the outer surface of the bottom of said part presents a teat surrounded by the well, the surface of whose bottom wall within the cup, is concave. This teat, at its very tip has a pair of intersecting slits therethrough, as indicated in the drawings, through which paste substance in the container is expelled when the latter is compressed, as generally shown in FIG. 3. The normal rest and closed position of the components constituting the part is shown in FIG. 2.
The tube or container, filled or partially filled with past substance, will always have such substance filling the part. When pressure is applied to the container, the part will become distended as shown in FIG. 3, where the teat or discharge nozzle extends out of the cup and is discharging. According to Schafler, the teat or nozzle has actually grown in length. Upon release of such pressure, the part will again assume its normal rest condition, as generally shown in FIG. 2, where the nozzle is retracted into the cup, has become shortened and the lips of its mouth are closed, all automatically, because of the springing back of the tensed comparatively thicker wall parts which constitute the nozzle tip and at least the major portion of the annular channel walls away from the nozzle, leaving the remainder of the bottom of said part relatively thin. According to Schafler, the aforementioned shape of the bottom wall of the well facilitates the lengthening of the teat when pressure is applied to the tube and the shortening of said teat when such pressure is released.
Still another prior art liquid dispenser bottle comprised of resiliently flexible material and having a relatively thin, resiliently flexible septum of circular planform seated on and spanning the dispenser outlet is illustrated in U.S. Pat. No. 4,133,457 issued to Klassen on Jan. 9, 1979. The flexible septum is sealingly clamped in place about its periphery of a dispenser nozzle cap. The septum has a 90.degree. butt cut slit formation defining at least one resiliently flexible valve flap integrally joined along a hinge area to the septum proper for outward deflection of the flap by internal liquid pressure when the dispenser is squeezed. The sepum is also formed with at least one tiny hole, preferably on or in the vicinity of the hinge line area to increase flexibility of the valve flap and to serve as a vent to greatly accelerate relaxation and normalization of the squeezed bottle wall.
Unfortunately, prior art structures of the aforementioned type have not proven completely satisfactory in providing a particularly preferred combination of features which are highly desirable for fluid materials. Namely: single handed dispensing of viscous fluids in response to manual forces applied to the package; spontaneous shut-off of product flow when the manual forces are removed or when the internal pressure of the package is otherwise reduced; and resistant to leakage when the package is stored in an inverted dispensing position over an extended period of time intermediate dispensing cycles.
Accordingly, it is an object of the present invention to provide a flexible storage and dispensing package comprising a resiliently deformable container equipped with a self-sealing valve which will permit discharge of the container's contents when externally applied forces generate a fluid pressure exceeding a predetermined threshold pressure, spontaneous product shut off when the manually applied forces are removed and resistance to leakage during handling even if the container is stored in an inverted position over an extended period of time intermediate dispensing cycles.
It is another object of the present invention to provide such a storage and dispensing package which provides a high degree of control over the amount of product dispensed.
It is a further object of the present invention to provide such a storage and dispensing package which is self-venting upon removal of said manually applied forces.
It is a further object of the present invention to provide such a storage and dispensing package which is inexpensive to manufacture.
It is still a further object of the present invention to provide such a storage and dispensing package with a minimum of moving parts to provide resistance to clogging and high reliability.
It is still a further object of the present invention to provide such a storage and dispensing package having a valve which is self-clearing upon the application of manual forces thereto.
It is still a further object of the present invention to provide such a storage and dispensing package which includes simple and inexpensive means for suspending or standing said package with the self-sealing valve downwardly oriented intermediate dispensing cycles.